A) LOADING ISSUES
Look for a well that has potential. Generally the ideal candidate is a good to average well that is on a natural decline and begins loading. Well A was a good well on a fairly steep production decline that began loading. It had fallen from about 400 mcf/day with 5 BO & 3 BW to about 30 mcf/day and no fluid in approximately one month. Our client had recently purchased Well A. The previous operator would swab occasionally and the well would increase from about 30mcf/day to 400 mcf/day only to load back up quickly and flow about 30 mcf/day with no fluid. After taking over operations we installed a conventional plunger lift system with a pad plunger. The well slowly increased from 30 mcf/day to the point where we were able to catch the plunger and let the well free flow. It improved to a free flow rate of 450 mcf/day with 5 BO & 3 BW. When the well would load we would drop the plunger periodically to unload the well, thus saving the cost of swabbing. This system paid out very quickly. As the well continued to decline we began running the plunger full time and eventually installed a bypass type plunger.
B) INCONSISTENT PRODUCTION & SCALE/PARAFFIN BUILD UP PREVENTION
Well B would flow from 100 to 300 mcf/day, but was very erratic. The pumper would occasionally shut the well in and let it build up for 24 hours before returning it to production. We installed a bypass type plunger lift system on this well that only required about 20 minutes of shut in time between plunger runs. This system worked well and made production much more stable.
Something that is often encountered in wells is paraffin and/or scale build up inside the tubing string. When installing this plunger system, we found a restricted ID in the tubing string due to scale build up. It took three days of slickline work to broach the tubing back to the appropriate ID before we could get the plunger to fall properly. Initially we ran a conventional solid bar stock "clean out" plunger in the well for a month to rattle and clean the tubing wall. We then installed a bypass plunger in the well that used a short shut-in cycle. The bypass plunger ran successfully and has kept the tubing clean and clear of any build up and has stabilized production.
C) REMOVING LIQUIDS WITHOUT SWABBING
Brammer Engineering drilled Well C in 2010. The well was perforated and swabbed tested but never stimulated. It was completed in a severely depleted reservoir. The well would not flow. It was swabbed on five occasions and tested through test equipment. After swabbing it would flow less than 20 mcf/day and would not sustain flow but would load up. We installed a conventional system with a pad type plunger and set it up with very conservative run times. The plunger ran successfully and started lifting about 5 BWPD. Gas and water rates increased and after approximately two weeks we caught the plunger and let the well free flow. The well eventually increased to a 600 mcf/day flow rate with about 15 BWPD. This saved the cost of continually swabbing the well and venting the well to the tank. We were able to unload the well via plunger into the gathering system. We also recovered the lost revenue of venting the gas to the tank and avoided releasing methane emissions into the atmosphere. The plunger system is still on the well and is still used off and on to unload the well without the use of a swab rig or venting. It has paid for itself many times.
In summary, plunger lift systems are one the least expensive and most efficient means to produce weak wells with the right operating conditions. These systems can also significantly reduce soap/foamer use on wells (we reduced one client's chemical costs by 40-50% by replacing foamer injection with plungers). We have seen the associated benefit of keeping the tubing clear of paraffin and scale build up with plunger systems. The new smart/logic control boxes increase or reduce flow times and shut in times keeping plungers running in optimal conditions. New plunger technology reduces shut-in time and allows for removal of more liquids from the well. The typical initial cost of a conventional plunger installation on a well without a packer has been around $10,000, which includes the plunger, catcher/lubricator, motor valve and controller, as well as slickline work to check tubing ID and broach if necessary.
Let us help you identify and evaluate candidates for plunger lift installations. Under the right circumstances, plungers can be great tools to increase production, cut operating costs, and extend the productive lives of many of your under-performing assets.
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